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<body>
  <header class="group-data" data-query="group">
    <h1>Web Performance Working Group</h1>
    <nav>
      <ul>
        <li>
          <a href="https://www.w3.org/2021/02/webperf.html">Charter</a>
        </li>
        <li data-query="services.*[type=repository]"><a href="https://www.w3.org/PM/Groups/repositories.html?gid=45211">GitHub</a></li>
        <li data-query="services.*[type=lists]"><a href="https://lists.w3.org/Archives/Public/public-web-perf/">Mailing
                list</a></li>
         
         
         
        <li data-query="services.*[type=twitter]"><a href="https://twitter.com/webperfwg">Twitter</a></li>
      </ul>
    </nav>
  </header>
  <main class="group-data" data-query="group">
    <section id="mission">
      <h2>Mission</h2>
      <p>The mission of the Web Performance Working Group is to provide methods to measure aspects of application performance of user agent features and APIs.</p>
    </section>
    <section id="specs">
      <h2>Specs</h2>
      <dl id="specList" data-query="specifications.*[latest-status!=Retired]">
          <div id="navigation-timing">
            <dt><a href="https://www.w3.org/TR/navigation-timing/">Navigation Timing</a> - <span class="status">Recommendation</span></dt>
            <dd><p>This document provides an interface for web applications to access timing information related to navigation and elements.</p></dd>
          </div>
        
          <div id="page-visibility">
            <dt><a href="https://www.w3.org/TR/page-visibility/">Page Visibility (Second Edition)</a> - <span class="status">Recommendation</span></dt>
            <dd><p> This specification defines a means for site developers to programmatically determine the current visibility state of the page in order to develop power and CPU efficient web applications. </p></dd>
          </div>
        
          <div id="performance-timeline">
            <dt><a href="https://www.w3.org/TR/performance-timeline/">Performance Timeline</a> - <span class="status">Recommendation</span></dt>
            <dd><p> This specification defines an interface for web applications to access timing information related to navigation and elements. It is used by other specifications, like User Timing. </p></dd>
          </div>
        
          <div id="resource-timing-1">
            <dt><a href="https://www.w3.org/TR/resource-timing-1/">Resource Timing Level 1</a> - <span class="status">Candidate Recommendation</span></dt>
            <dd><p>This specification defines an interface for web applications to access timing information related to HTML elements.</p></dd>
          </div>
        
          <div id="beacon">
            <dt><a href="https://www.w3.org/TR/beacon/">Beacon</a> - <span class="status">Candidate Recommendation</span></dt>
            <dd><p>This specification defines an interoperable means for site developers to asynchronously transfer data from the user agent to a web server, with the user agent taking the responsibility to eventually send the data.</p></dd>
          </div>
        
          <div id="longtasks-1">
            <dt><a href="https://www.w3.org/TR/longtasks-1/">Long Tasks API 1</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This document defines an API that web page authors can use to detect presence of “long tasks” that monopolize the UI thread for extended periods of time and block other critical tasks from being executed - e.g. reacting to user input.</p></dd>
          </div>
        
          <div id="paint-timing">
            <dt><a href="https://www.w3.org/TR/paint-timing/">Paint Timing 1</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This document defines an API that can be used to capture a series of key moments (First Paint, First Contentful Paint) during pageload which developers care about.</p></dd>
          </div>
        
          <div id="requestidlecallback">
            <dt><a href="https://www.w3.org/TR/requestidlecallback/">Cooperative Scheduling of Background Tasks</a> - <span class="status">Proposed Recommendation</span></dt>
            <dd><p>The requestIdleCallback method is a more appropriate way for scheduling background tasks during times when the browser would otherwise be idle.</p></dd>
          </div>
        
          <div id="device-memory-1">
            <dt><a href="https://www.w3.org/TR/device-memory-1/">Device Memory</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This document defines a HTTP Client Hint header to surface device capability for memory i.e. device RAM, in order to enable web apps to customize content depending on device memory constraints.</p></dd>
          </div>
        
          <div id="reporting-1">
            <dt><a href="https://www.w3.org/TR/reporting-1/">Reporting API</a> - <span class="status">Working Draft</span></dt>
            <dd><p>The reporting API provides a generic reporting framework which allows Web developers to associate a set of named reporting endpoints with an origin. Various platform features (like Content Security Policy, Network Error Reporting, and others) will use these endpoints to deliver feature-specific reports in a consistent manner.</p></dd>
          </div>
        
          <div id="network-error-logging-1">
            <dt><a href="https://www.w3.org/TR/network-error-logging-1/">Network Error Logging</a> - <span class="status">Working Draft</span></dt>
            <dd><p>Navigation Error Logging defines an API to store and retrieve error
data related to the previous navigations of a document.</p></dd>
          </div>
        
          <div id="user-timing-2">
            <dt><a href="https://www.w3.org/TR/user-timing-2/">User Timing Level 2</a> - <span class="status">Recommendation</span></dt>
            <dd><p>This specification defines an interface to help web developers measure the performance of their applications by giving them access to high precision timestamps.</p></dd>
          </div>
        
          <div id="preload">
            <dt><a href="https://www.w3.org/TR/preload/">Preload</a> - <span class="status">Candidate Recommendation</span></dt>
            <dd><div><p>This specification defines the  relationship of the HTML Link Element ().</p><code>preload</code><code>&lt;link&gt;</code></div></dd>
          </div>
        
          <div id="timing-entrytypes-registry">
            <dt><a href="https://www.w3.org/TR/timing-entrytypes-registry/">Timing Entry Names Registry</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This registry is intended to provide a central location for enumerating identified interface types of PerformanceEntry objects, which contain various data metrics for the the full lifecycle of a web application.</p></dd>
          </div>
        
          <div id="performance-timeline-2">
            <dt><a href="https://www.w3.org/TR/performance-timeline-2/">Performance Timeline Level 2</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This specification extends the High Resolution Time specification by providing methods to store and retrieve high resolution performance metric data.</p></dd>
          </div>
        
          <div id="hr-time-2">
            <dt><a href="https://www.w3.org/TR/hr-time-2/">High Resolution Time Level 2</a> - <span class="status">Recommendation</span></dt>
            <dd><p>This specification defines a JavaScript interface that provides the current time in sub-millisecond resolution and such that it is not subject to system clock skew or adjustments.</p></dd>
          </div>
        
          <div id="server-timing">
            <dt><a href="https://www.w3.org/TR/server-timing/">Server Timing</a> - <span class="status">Working Draft</span></dt>
            <dd><p>Server Timing, part of the performance timeline metrics, provides API
access to request-response cycle performance metrics communicated from
the server to the user agent.</p></dd>
          </div>
        
          <div id="resource-hints">
            <dt><a href="https://www.w3.org/TR/resource-hints/">Resource Hints</a> - <span class="status">Working Draft</span></dt>
            <dd><p>Resource Hints provides hints that authors may use to assist the user
agent in fetching resources to improve page performance.</p></dd>
          </div>
        
          <div id="navigation-timing-2">
            <dt><a href="https://www.w3.org/TR/navigation-timing-2/">Navigation Timing Level 2</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This document provides an interface for web applications to access timing information related to navigation and elements.</p></dd>
          </div>
        
          <div id="user-timing-3">
            <dt><a href="https://www.w3.org/TR/user-timing-3/">User Timing Level 3</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This specification defines an interface to help web developers measure the performance of their applications by giving them access to high precision timestamps.</p></dd>
          </div>
        
          <div id="resource-timing-2">
            <dt><a href="https://www.w3.org/TR/resource-timing-2/">Resource Timing Level 2</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This specification defines an interface for web applications to access the complete timing information for resources in a document.</p></dd>
          </div>
        
          <div id="page-visibility-2">
            <dt><a href="https://www.w3.org/TR/page-visibility-2/">Page Visibility Level 2</a> - <span class="status">Candidate Recommendation Snapshot</span></dt>
            <dd><p>This specification defines a means to programmatically determine the visibility state of a document. This can aid in the development of resource efficient web applications.</p></dd>
          </div>
        
          <div id="hr-time-3">
            <dt><a href="https://www.w3.org/TR/hr-time-3/">High Resolution Time</a> - <span class="status">Working Draft</span></dt>
            <dd><p>This specification defines an API that provides the current time in sub-millisecond resolution and such that it is not subject to system clock skew or adjustments.</p></dd>
          </div>
        </dl>
    </section>
    <section id="repos">
      <h2>Repos</h2>
      <dl id="repoList" data-query="repositories">
          <div id="w3c-beacon">
            <dt><a href="https://github.com/w3c/beacon/">w3c/beacon</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Beacon</p>
            </dd>
          </div>
        
          <div id="w3c-device-memory">
            <dt><a href="https://github.com/w3c/device-memory/">w3c/device-memory</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Device Memory</p>
            </dd>
          </div>
        
          <div id="w3c-hr-time">
            <dt><a href="https://github.com/w3c/hr-time/">w3c/hr-time</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>High Resolution Time</p>
            </dd>
          </div>
        
          <div id="w3c-longtasks">
            <dt><a href="https://github.com/w3c/longtasks/">w3c/longtasks</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Long Task API</p>
            </dd>
          </div>
        
          <div id="w3c-navigation-timing">
            <dt><a href="https://github.com/w3c/navigation-timing/">w3c/navigation-timing</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Navigation Timing</p>
            </dd>
          </div>
        
          <div id="w3c-network-error-logging">
            <dt><a href="https://github.com/w3c/network-error-logging/">w3c/network-error-logging</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Network Error Logging</p>
            </dd>
          </div>
        
          <div id="w3c-page-visibility">
            <dt><a href="https://github.com/w3c/page-visibility/">w3c/page-visibility</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Page Visibility</p>
            </dd>
          </div>
        
          <div id="w3c-paint-timing">
            <dt><a href="https://github.com/w3c/paint-timing/">w3c/paint-timing</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Paint Timing</p>
            </dd>
          </div>
        
          <div id="w3c-performance-timeline">
            <dt><a href="https://github.com/w3c/performance-timeline/">w3c/performance-timeline</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Performance Timeline</p>
            </dd>
          </div>
        
          <div id="w3c-preload">
            <dt><a href="https://github.com/w3c/preload/">w3c/preload</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Preload</p>
            </dd>
          </div>
        
          <div id="w3c-reporting">
            <dt><a href="https://github.com/w3c/reporting/">w3c/reporting</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Reporting API</p>
            </dd>
          </div>
        
          <div id="w3c-requestidlecallback">
            <dt><a href="https://github.com/w3c/requestidlecallback/">w3c/requestidlecallback</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Cooperative Scheduling of Background Tasks</p>
            </dd>
          </div>
        
          <div id="w3c-resource-hints">
            <dt><a href="https://github.com/w3c/resource-hints/">w3c/resource-hints</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Resource Hints</p>
            </dd>
          </div>
        
          <div id="w3c-resource-timing">
            <dt><a href="https://github.com/w3c/resource-timing/">w3c/resource-timing</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Resource Timing</p>
            </dd>
          </div>
        
          <div id="w3c-server-timing">
            <dt><a href="https://github.com/w3c/server-timing/">w3c/server-timing</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>Server Timing</p>
            </dd>
          </div>
        
          <div id="w3c-user-timing">
            <dt><a href="https://github.com/w3c/user-timing/">w3c/user-timing</a>
              <span class="type">(rec-track)</span></dt>
            <dd>
              <p>User Timing</p>
            </dd>
          </div>
        
          <div id="w3c-perf-security-privacy">
            <dt><a href="https://github.com/w3c/perf-security-privacy/">w3c/perf-security-privacy</a>
              <span class="type">(note)</span></dt>
            <dd>
              <p>Performance APIs, Security and Privacy</p>
            </dd>
          </div>
        
          <div id="w3c-perf-timing-primer">
            <dt><a href="https://github.com/w3c/perf-timing-primer/">w3c/perf-timing-primer</a>
              <span class="type">(note)</span></dt>
            <dd>
              <p>A Primer for Web Performance Timing APIs</p>
            </dd>
          </div>
        
          <div id="w3c-timing-entrytypes-registry">
            <dt><a href="https://github.com/w3c/timing-entrytypes-registry/">w3c/timing-entrytypes-registry</a>
              <span class="type">(note)</span></dt>
            <dd>
              <p>Timing Entry Names Registry</p>
            </dd>
          </div>
        
          <div id="w3c-charter-webperf">
            <dt><a href="https://github.com/w3c/charter-webperf/">w3c/charter-webperf</a>
              <span class="type">(process)</span></dt>
            <dd>
              <p>Web Performance Group charter</p>
            </dd>
          </div>
        
          <div id="w3c-web-performance">
            <dt><a href="https://github.com/w3c/web-performance/">w3c/web-performance</a>
              <span class="type">(homepage)</span></dt>
            <dd>
              <p>W3C Web Performance Working Group repo</p>
            </dd>
          </div>
        
          <div id="w3c-webperf-dashboard">
            <dt><a href="https://github.com/w3c/webperf-dashboard/">w3c/webperf-dashboard</a>
              <span class="type">(tool)</span></dt>
            <dd>
              <p>W3C webperf issue tracker</p>
            </dd>
          </div>
        </dl>
    </section>
    <!--
    <section id="events">
      <h2>Face-to-face meetings</h2>
      <div data-if="events.*">
        <dl id="eventList" data-query="events">
          <div>
            <dt><a href="${href}">${summary}</a></dt>
            <dd>
              <p>${location} - ${start} to ${end}</p>
            </dd>
          </div>
        </dl>
        <p>Group has no face-to-face meetings scheduled.</p>
      </div>
    </section>
    -->
    <section id="Contacts">
      <h2>Contacts</h2>
      <dl>
        <dt>Chairs:</dt>
        <dd id="chairs">
          <span data-query="chairs">
              <a href="https://github.com/nicjansma">Nic Jansma</a>,
            
              <a href="https://github.com/yoavweiss">Yoav Weiss</a>,
            </span>
        </dd>
        <dt>Team contacts:</dt>
        <dd id="team-contacts">
          <span data-query="team-contacts">
              <a href="https://github.com/caribouW3">Carine Bournez</a>,
              </span>
        </dd>
      </dl>
    </section>
    <section>
      <h2>Members</h2>
      <ul id="participations" data-query="participations.*[individual=false]">
        <li>Adobe</li>
      
        <li>Airbnb Inc</li>
      
        <li>Akamai Technologies</li>
      
        <li>Alibaba Group</li>
      
        <li>Apple, Inc.</li>
      
        <li>Baidu, Inc.</li>
      
        <li>British Broadcasting Corporation</li>
      
        <li>Cloudflare</li>
      
        <li>Facebook</li>
      
        <li>Fastly</li>
      
        <li>Google LLC</li>
      
        <li>Microsoft Corporation</li>
      
        <li>Mozilla Foundation</li>
      
        <li>Salesforce</li>
      
        <li>Shopify</li>
      
        <li>The New York Times</li>
      
        <li>Wikimedia Foundation</li>
      </ul>
    </section>
    <section>
        <h2>Invited Experts</h2>
        <ul id="participations" data-query="participations.*[invited-expert=true]">
          <li>Marcos Caceres</li>
        
          <li>Michelle Vu</li>
        
          <li>Noam Rosenthal</li>
        
          <li>Patrick Meenan</li>
        
          <li>Peter Perlepes</li>
        </ul>
      </section>
  </main>
  <footer class="group-data" data-query="group">
    <nav>
      <ul>
        <li>
          <a href="https://www.w3.org/Consortium/cepc/">Code of conduct</a>
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